Systems and methods for providing resource isolation in a shared computing environment using reinforcement learning (RL) techniques are disclosed. A resource isolation mechanism may be applied in a shared storage system, or database service, that limits the resource utilization of each namespace to its specified allocation. For example, the resource isolation mechanism may be used to limit the I/O utilization of database applications in a shared computing system (e.g., a system supporting a database service) to a specified limit. In such embodiments, RL techniques may be applied to the system to automatically control the rate of queries made by an application. RL techniques, such as those based on the State-Action-Reward-State-Action (SARSA) method may be effective in controlling the I/O utilization of database applications for different workloads. RL techniques may be applied globally by the service, or may be applied to particular subscribers, applications, shared resources, namespaces, or query types.